Production of interferon MCQs With Answer

Production of interferon MCQs With Answer

by

Production of interferon MCQs With Answer

This quiz set focuses on the production, processing, characterization and regulatory considerations of interferons as relevant to M.Pharm students specializing in Advanced Pharmaceutical Biotechnology. It covers recombinant expression platforms (bacterial, yeast, insect and mammalian), upstream bioreactor strategies, secretion and refolding approaches, downstream purification and viral/endotoxin clearance, analytical and potency assays, post‑translational modifications such as glycosylation and pegylation, and critical quality attributes. The questions are designed to test conceptual understanding and practical decision‑making encountered during scale‑up and manufacture of interferon therapeutics, emphasizing deeper process and product-related knowledge rather than superficial facts.

Q1. Which of the following is classified as a Type II interferon?

  • Interferon-alpha
  • Interferon-beta
  • Interferon-gamma
  • Interferon-lambda

Correct Answer: Interferon-gamma

Q2. Historically, which host has been most commonly used for large‑scale recombinant production of clinical interferon-alpha (e.g., IFN alfa-2b)?

  • Pichia pastoris yeast
  • Escherichia coli
  • Chinese hamster ovary (CHO) cells
  • Baculovirus-infected insect cells

Correct Answer: Escherichia coli

Q3. What is the major biochemical problem encountered when expressing human interferon in E. coli that often necessitates downstream refolding?

  • Hyper‑glycosylation in the cytosol
  • Formation of inclusion bodies containing aggregated protein
  • Excessive disulfide bond formation in the periplasm
  • Proteolytic hyper‑cleavage producing unstable fragments

Correct Answer: Formation of inclusion bodies containing aggregated protein

Q4. Which promoter is commonly used in Pichia pastoris for high‑level methanol‑induced expression of recombinant interferon?

  • GAP (constitutive glyceraldehyde‑3‑phosphate dehydrogenase) promoter
  • AOX1 (alcohol oxidase 1) promoter
  • CMV (cytomegalovirus) promoter
  • lac promoter

Correct Answer: AOX1 (alcohol oxidase 1) promoter

Q5. Which affinity tag and corresponding purification method is most commonly used to simplify recombinant interferon purification?

  • GST tag with glutathione affinity chromatography
  • FLAG tag with anti‑FLAG immunoaffinity chromatography
  • 6xHis tag with immobilized metal affinity chromatography (IMAC)
  • Maltose binding protein (MBP) with amylose resin

Correct Answer: 6xHis tag with immobilized metal affinity chromatography (IMAC)

Q6. Why is pegylation commonly applied to therapeutic interferons?

  • To increase receptor binding affinity and potency
  • To reduce half‑life and accelerate clearance
  • To increase serum half‑life and reduce immunogenicity
  • To add glycosylation patterns identical to human cells

Correct Answer: To increase serum half‑life and reduce immunogenicity

Q7. Which assay is routinely used to determine the biological potency of interferon preparations and reported in International Units (IU)?

  • ELISA for interferon concentration (ng/mL)
  • Antiviral bioassay measuring protection against viral cytopathic effect
  • SDS‑PAGE densitometry for purity assessment
  • Mass spectrometry for molecular mass determination

Correct Answer: Antiviral bioassay measuring protection against viral cytopathic effect

Q8. How does glycosylation typically affect interferon therapeutic proteins?

  • It always decreases biological activity by steric hindrance
  • It has no effect on stability or receptor interactions
  • It can modulate stability, circulating half‑life and receptor binding
  • It converts interferon into a protease

Correct Answer: It can modulate stability, circulating half‑life and receptor binding

Q9. Which downstream technique is specifically useful for reducing endotoxin levels in interferon produced from E. coli?

  • Protein A affinity chromatography
  • Triton X‑114 phase separation
  • Size exclusion chromatography as the only step
  • Lyophilization

Correct Answer: Triton X‑114 phase separation

Q10. For production of a glycosylated form of interferon-beta with human‑like N‑glycans, which expression system is preferred?

  • Escherichia coli cytosolic expression
  • Pichia pastoris with AOX1 promoter
  • Mammalian cells such as CHO
  • Baculovirus expression in insect cells

Correct Answer: Mammalian cells such as CHO

Q11. What is a commonly used method to recover biologically active interferon from inclusion bodies?

  • Direct injection without processing
  • Stepwise dialysis or controlled dilution refolding into refolding buffer
  • Heating to 95°C to solubilize aggregates
  • Treatment with glycosyltransferases

Correct Answer: Stepwise dialysis or controlled dilution refolding into refolding buffer

Q12. What is the principal role of adding a signal peptide to a recombinant interferon expression construct for secretion?

  • To increase translation speed in the cytosol
  • To direct the protein to the secretory pathway for periplasmic/ER translocation and disulfide bond formation
  • To tag the protein for proteasomal degradation
  • To add glycosylation sites directly in the signal peptide

Correct Answer: To direct the protein to the secretory pathway for periplasmic/ER translocation and disulfide bond formation

Q13. Which analytical technique provides an estimate of interferon purity and apparent molecular weight under denaturing conditions?

  • Size exclusion HPLC exclusively
  • SDS‑PAGE with Coomassie staining
  • Biacore surface plasmon resonance
  • Endotoxin assay

Correct Answer: SDS‑PAGE with Coomassie staining

Q14. Type I interferons (e.g., IFN‑alpha and IFN‑beta) exert their effects by binding to which receptor complex?

  • IFNGR1/IFNGR2 complex
  • IFNAR1/IFNAR2 complex
  • IL‑2 receptor alpha/beta
  • Toll‑like receptor 4 (TLR4)

Correct Answer: IFNAR1/IFNAR2 complex

Q15. Which bioreactor cultivation strategy is most suitable for continuous high volumetric productivity and minimal product residence time to reduce proteolysis of secreted interferon from mammalian cells?

  • Batch culture with single harvest at end
  • Fed‑batch culture
  • Perfusion culture with continuous harvest
  • Static flask culture

Correct Answer: Perfusion culture with continuous harvest

Q16. Which single upstream culture parameter most directly influences glycosylation microheterogeneity of recombinant interferon made in mammalian cells?

  • Culture pH
  • Cell line passage number only
  • Antifoam concentration
  • Type of stirrer blade

Correct Answer: Culture pH

Q17. What is the main purpose of codon optimization when designing an interferon gene for expression in a heterologous host?

  • To introduce new glycosylation sites
  • To match host tRNA abundance and improve translation efficiency
  • To alter the protein primary sequence and function
  • To add disulfide bonds to the protein

Correct Answer: To match host tRNA abundance and improve translation efficiency

Q18. Which regulatory concern is particularly critical for interferon produced in bacterial hosts compared with mammalian hosts?

  • Excessive human‑like glycosylation
  • Endotoxin contamination
  • Viral contaminants from human cell lines
  • Over‑glycosylation leading to aggregation

Correct Answer: Endotoxin contamination

Q19. How is specific biological activity of an interferon preparation most commonly expressed?

  • mg/mL concentration by UV absorbance
  • International Units per mg (IU/mg) determined by bioassay
  • Number of disulfide bonds per molecule
  • Ratio of glycoforms by mass spectrometry

Correct Answer: International Units per mg (IU/mg) determined by bioassay

Q20. Which downstream unit operation is a standard viral clearance method used for removal of potential adventitious viruses during interferon purification?

  • Ion exchange chromatography only
  • Nanofiltration (virus‑retentive filtration)
  • Dialysis against PBS
  • Ultracentrifugation without membrane filtration

Correct Answer: Nanofiltration (virus‑retentive filtration)

Leave a Comment